1 overview of electrical engineering lecture 8a: introduction to engineering
TRANSCRIPT
1
Overview of Electrical Overview of Electrical EngineeringEngineering
Lecture 8A:Lecture 8A:
Introduction to Introduction to EngineeringEngineering
2Lecture 1
Foundations of Electrical Foundations of Electrical EngineeringEngineering
ElectrophysicsElectrophysics Information Information
(Communications) (Communications) TheoryTheory
Digital LogicDigital Logic
3Lecture 1
Foundations of Electrical Foundations of Electrical EngineeringEngineering
ElectrophysicsElectrophysics:: Fundamental theories of physics Fundamental theories of physics
and important special cases.and important special cases. Phenomenological/behavioral Phenomenological/behavioral
models for situations where the models for situations where the rigorous physical theories are too rigorous physical theories are too difficult to apply.difficult to apply.
4Lecture 1
Hierarchy of Physics Theories Hierarchy of Physics Theories Involved in the Study of Involved in the Study of Electrical EngineeringElectrical Engineering
Quantum electrodynamicsQuantum electrodynamics Quantum mechanicsQuantum mechanics
Schrödinger equationSchrödinger equation Classical electromagneticsClassical electromagnetics
ElectrostaticsElectrostatics ElectrodynamicsElectrodynamics Circuit theoryCircuit theory Geometric opticsGeometric optics
5Lecture 1
Maxwell’s EquationsMaxwell’s Equations
6Lecture 1
Information TheoryInformation Theory Originally developed by Claude Originally developed by Claude
Shannon of Bell Labs in the 1940s.Shannon of Bell Labs in the 1940s. InformationInformation is defined as a symbol that is defined as a symbol that
is uncertain at the receiver.is uncertain at the receiver. The fundamental quantity in The fundamental quantity in
information theory is information theory is channel capacitychannel capacity – – the maximum rate that information the maximum rate that information can be exchanged between a can be exchanged between a transmitter and a receiver.transmitter and a receiver.
The material in this slide and the next has been adapted from material from www.lucent.com/minds/infotheory.
7Lecture 1
Information TheoryInformation Theory
Defines relationships between Defines relationships between elements of a communications elements of a communications system. For example,system. For example, Power at the signal sourcePower at the signal source Bandwidth of the systemBandwidth of the system NoiseNoise InterferenceInterference
Mathematically describes the Mathematically describes the principals of data compression.principals of data compression.
8Lecture 1
Exercise: What is Exercise: What is Information?Information?
Message with redundancy:Message with redundancy: ““Many students are likely to fail Many students are likely to fail
that exam.”that exam.” Message coded with less Message coded with less
redundancy:redundancy: ““Mny stdnts are lkly to fail tht Mny stdnts are lkly to fail tht
exm.”exm.”Claude Shannon, founder of Information Theory
9Lecture 1
Digital LogicDigital Logic Based on logic gates, truth Based on logic gates, truth
tables, and combinational and tables, and combinational and sequential logic circuit design sequential logic circuit design
Uses Boolean algebra and Uses Boolean algebra and Karnaugh maps to develop Karnaugh maps to develop
minimized minimized
logic circuits. logic circuits.
10Lecture 1
EE SubdisciplinesEE Subdisciplines
Power SystemsPower Systems ElectromagneticsElectromagnetics Solid State Solid State Communication/Signal Communication/Signal
ProcessingProcessing ControlsControls Analog/Digital DesignAnalog/Digital Design
11Lecture 1
Power SystemsPower Systems
Generation of electrical energyGeneration of electrical energy Storage of electrical energyStorage of electrical energy Distribution of electrical energyDistribution of electrical energy Rotating machinery-generators, Rotating machinery-generators,
motorsmotors
12Lecture 1
ElectromagneticsElectromagnetics
Propagation of electromagnetic Propagation of electromagnetic energyenergy
AntennasAntennas Very high frequency signalsVery high frequency signals Fiber opticsFiber optics
13Lecture 1
Solid StateSolid State
DevicesDevices TransistorsTransistors Diodes (LED’s, Laser diodes)Diodes (LED’s, Laser diodes) PhotodetectorsPhotodetectors
Miniaturization of electrical Miniaturization of electrical devicesdevices
Integration of many devices on a Integration of many devices on a single chipsingle chip
14Lecture 1
Communications/Signal Communications/Signal Proc.Proc.
Transmission of information Transmission of information electrically and opticallyelectrically and optically
Modification of signalsModification of signalsenhancementenhancementcompressioncompressionnoise reductionnoise reductionfilteringfiltering
15Lecture 1
ControlsControls
Changing system inputs to Changing system inputs to obtain desired outputsobtain desired outputs
FeedbackFeedback StabilityStability
16Lecture 1
Digital DesignDigital Design
Digital (ones and zeros) signals and Digital (ones and zeros) signals and hardwarehardware
Computer architecturesComputer architectures Embedded computer systemsEmbedded computer systems
MicroprocessorsMicroprocessors MicrocontrollersMicrocontrollers DSP chipsDSP chips Programmable logic devices (PLDs)Programmable logic devices (PLDs)
17Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
ATCi Corporate Headquarters450 North McKemyChandler, AZ 85226 USA
SimulsatParabolic
Horn feed
Multiple horn feeds
18Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
Incoming plane wave is focused by reflector at location of horn feed.
Geometric Optics
19Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
Feed horn is designed so that it will illuminate the reflector in such a way as to maximize the aperture efficiency.
Maxwell’sequations
20Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
Feed horn needs to be able to receive orthogonal linear polarizations (V-pol and H-pol) and maintain adequate isolation between the two channels.
V-pol
H-pol
21Lecture 1
A planar orthomode transducer (OMT) is used to achieve good isolation between orthogonal linear polarizations.
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
Maxwell’s Equations (“Full-Wave Solution”)
22Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
Horn
Feed waveguide (WR 229)
To LNB
Stripline circuit with OMT, ratrace and WR229 transitions
Maxwell’sequations
23Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
Single-ended probe
Differential-pair probes
Ratrace hybrid
WR229Transitions
50 ohm transmission line
Layout of the stripline trace layer
Vias
Circuit Theory
24Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
The two linear polarizations each are fed to a LNB (low noise block).
LNB
LNB
25Lecture 1
Case Study: C/Ku Band Earthstation Case Study: C/Ku Band Earthstation Antennas Antennas
LNB:
LNA Mixer
IF Output:950-1750 MHz(To Receiver)
Local Oscillator
BPF
Circuit Theory,
Behavioral Models,
Information Theory